High-Performance MoS2 Field-Effect Transistors Enabled by Chloride Doping: Record Low Contact Resistance (0.5 k Omega.mu m) and Record High Drain Current (460 mu A/mu m)

In this paper, we report a novel chemical doping technique to reduce the contact resistance (R-c) of transition metal dichalcogenides (TMDs) - eliminating two major roadblocks (namely, doping and high R-c) towards demonstration of high-performance TMDs fieldeffect transistors (FETs). By using 1,2 dichloroethane (DCE) as the doping reagent, we demonstrate an active n-type doping density > 2x10(19) cm(-3) in a few-layer MoS2 film. This enabled us to reduce the R-c value to a record low number of 0.5 k Omega.mu m, which is similar to 10xlower than the control sample without doping. The corresponding specific contact resistivity (rho(c)) is found to decrease by two orders of magnitude. With such low R-c, we demonstrate 100 nm channel length (L-ch) MoS2 FET with a drain current (I-ds) of 460 mu A/mu m at V-ds = 1.6 V, which is twice the best value reported so far on MoS2 FETs.